Abstract: The transition to the ambulatory setting following hospital discharge is a vulnerable time for patients. One important patient safety concern is failure of responsible providers to reliably follow up test results finalized after a patient is discharged. Such failure can lead to delays in diagnosis, missed treatment opportunities, redundant ordering of tests, and subsequent patient harm. Automated systems that ensure timely notification of these test results to responsible providers have the potential to mitigate these well documented problems and improve health care quality and safety. The goals of this project are to create an information technology-based automatic notification system to prompt responsible physicians of test results finalized after discharge and to evaluate the impact of this system on physician awareness of these test results. In the first phase of this study, the components of the system will be designed. These include 1) a query of all tests whose final results are pending at the time of discharge, 2) a query for the identity and email addresses of the patient's responsible inpatient and ambulatory provider, 3) logic to exclude routinely ordered inpatient tests to avoid provider alert fatigue, 4) automatic email notification of finalized test results to responsible providers once they are available, and 5) documentation of these results in the ambulatory electronic medical record. The system is designed to facilitate timely communication and the creation of a collaborative plan of care among inpatient and outpatient providers during a patient's transition to the ambulatory setting. A cluster randomized controlled trial will be conducted to measure the impact of such a system on physician awareness. To minimize contamination, both inpatient and ambulatory providers will be randomized, and patients will only be enrolled if both responsible physicians are in the same arm of the study. Study subjects will include patients discharged from the inpatient general medicine and cardiology services at Brigham and Women's Hospital. The primary outcome will be awareness of all post-discharge test results among responsible providers. Secondary outcomes will include user satisfaction, awareness of actionable test results (as judged by providers), and whether appropriate actions are subsequently taken in response to these results (based on electronic medical record review). Physician awareness will be determined using an email survey to providers 72 hours after the first finalized test result is available. The primary outcome will be analyzed as the proportion of test results per patient of which a provider is aware using binomial logistic regression. General estimating equations will be used to adjust for patient and physician characteristics and to cluster by physician. Over a six-month study period, 450 patients will be enrolled in order to provide adequate power to detect an improvement in awareness from 40% to 60% of results. The results of this study will inform future efforts to optimize this type of intervention both at BWH and at other institutions trying to solve this important patient safety problem.